Geoscience Reference
In-Depth Information
this work is focused on the practical needs of environmental management and
practitioners sit across the disciplinary boundaries of (bio-)geography and
ecology.
Two things characterise these parallels. First, despite the work across disciplines,
they still maintain a relatively disconnected approach. In some respects, this discon-
nectedness relates to the restricted spatial scale of observation (Eagleson's attempts
at global ecohydrology notwithstanding), while in others it relates to the lack of
development of strong interdisciplinary ties, or ties that are seldom more than
bilateral. Secondly, these strands of Earth-surface research were not well connected
to work on the atmosphere, which would be central to the ESS project. In part, this
disjuncture is due to the decline of exposure to atmospheric sciences. They are
decreasingly taught within geography departments - due to their perception as being
diffi cult or too mathematical - and never really had a home within biological
science. A notable exception again is the work of Eagleson, coming as it does from
a heavily mathematical, engineering perspective in hydrology. However, there have
been other key exceptions. Raymo's work on the linkages between plate tectonic
activity, weathering and CO
2
release to the atmosphere causing feedbacks that
potentially produced the Quaternary glaciations (e.g. Raymo, 1994), shows arche-
typal ESS interactions, even if it does operate on much longer timescales. Charney
(1975), working from a meteorological perspective, pointed out the signifi cant
potential feedbacks between vegetation and climate in the Sahel. More recent work
has tried to develop this theory, generally from a hydrological or environmental
science focus, but including the atmospheric linkages (e.g. Entekhabi et al., 1992).
The key outcome seems to be that modelling studies (e.g. Xue and Shukla, 1993;
Claussen, 1997; Zeng et al., 1999; Zhou et al., 2007) support the theory, while
observations, including remote sensing (e.g. Jackson and Idso, 1975; Wendler and
Eaton, 1983) fi nd problems with it.
These examples suggest major weaknesses with the argument that 'ESS
is
physical
geography'. Physical geographers have tended to have an overly reductionist focus
that has led them to concentrate on very small-scale processes without linking them
back to the larger scale. They also tend to lack the appropriate tools for the model-
ling approach to ESS given the quantitative paradox (that statistics are a require-
ment while mathematical modelling is considered a minority interest) inherent in
the syllabi of many university departments. Church (1998; 2005) has discussed the
appropriation of ESS into mainstream geology and its implications for physical
geographers, especially geomorphologists, from a similar perspective. That geomor-
phologists may have missed the boat seems inexcusable to Church, given that the
boat was moving at continental drift pace.
To what extent can ecologists be said to have fared any better? Given the bicam-
eral defi nition of the ESS blueprint, ecological work should inform understanding
of the behaviour of the whole Earth system in detail. Nitta (1994) described an
early example of how an experimental facility might be used to inform the function-
ing of the biosphere elements of ESS. Notwithstanding a major conference on using
understanding of linkages between plants and the atmosphere over geological tim-
escales in late 2001 (Pataki, 2002), some limited work on forest carbon (White and
Nemani, 2003) and the limited ecohydrological and landscape ecological work dis-
cussed above, ecology as a discipline seems as unimpressed with ESS as geographers
have been. A recent major review of plant response to CO
2
changes (Körner, 2006)
totally fails to mention ESS.
